OK small, vague, potentially unhelpful hint:
It might be worth drawing a scale picture of the recipe based on descriptions in the game, paying particular attention to size and shape.
A less vague hint:
The recipe isn’t as buoyant as you think.
At least that’s what I think is the problem. That puzzle totally defeated me, like you I kept trying the strangest things and I never understood why it wasn’t working. Frustrating as all get-out.
So I just failed to pick up an item, which is what stumped me with the tea puzzle.
After a two month hiatus having to do with moving house and getting a new PC, I found that getting back into the game was psychologically difficult. So I’m going to leave the endgame for another time, when I can play the entire game again from scratch, and Ill move forward with a new game in the Variomatic.
Wow. I’d find it difficult to motivate myself to replay such a demanding game from scratch.
…well, I DID replay all five Zork games years later, come to think of it.
But still.
Im sure it will be easier next time. And to be fair, this was the third time I tried the game, and every time I’ve come a lot further than the time before. 
Bear in mind that the ending is significantly different depending on whether you’ve earned the lousy last point or not. (Did anyone mention that? I don’t think anyone mentioned that.)